This invention relates generally to wall-to-wall carpeting. More particularly, the invention is concerned with an improvement in pressure sensitive adhesive carpet cushion and carpet laying systems, wherein the adhesive carpet cushion is made more cost effective and efficient in use.
A wall-to-wall carpet laying system developed by the present applicant and known by the trademark STEP-LOC has become a very important alternative to the conventional system using the so-called tackless strips and requiring stretching of the carpet from wall to wall. As disclosed in the applicant's copending application Ser. No. 243,606 , and the applicant's U.S. Pat. Nos. 4,797,170 and 4,557,774, a carpet cushion having the required thickness, density and compressibility may be pre-coated on either one or both sides with a pressure sensitive adhesive. The adhesive may be a water based pressure sensitive adhesive, such as an acrylic adhesive, or it may be a hot melt pressure sensitive adhesive, the latter being particularly advantageous for use on cushion materials which are highly porous but are not sealed. As further disclosed in the patents and the copending application, the cushion may employ a scrim webbing to improve dimensional stability.
The disclosures of Pat. Nos. 4,557,774 and 4,797,170, as well as the disclosure of copending application Ser. No. 243,606, are incorporated herein by reference.
Pat. No. 4,797,170 in particular discloses a wall-to-wall carpeting system involving a carpet cushion having pressure sensitive adhesive on only one surface of the cushion. Such a one-sided adhesive carpet cushion can be used to adhere the cushion to the floor, with additional adhesive used on the job to adhere the carpet down to the top surface of the cushion; or it can be used in the reverse orientation, with on the job adhesive to secure the cushion to the floor and the preapplied pressure sensitive adhesive of the cushion used to secure the carpet backing down against the top surface of the carpet cushion. The one-sided system has the versatility of being adaptable to either manner of use.
However, an aggressively tacky pressure sensitive adhesive, of the type which is preferred for use in a tackless, stretchless adhesive carpet cushion system as in the present invention, will sometimes adhere strongly to the non-adhesive coated opposite surface in roll storage, particularly if the cushion is rolled very tightly or in the event a compressive load is pushed against the roll. Such loading often occurs when a heavy load of additional cushion rolls or carpeting or other inventory is placed over a rolled adhesive carpet cushion. When the layers are pulled apart on unrolling of the cushion, damage can occur to an unprotected cushion surface.
In Pat. No. 4,797,170, the subject of rolled storage and transport of the carpet cushion was discussed. It was disclosed that a release film should be placed over the adhesive surface before rolling the cushion into a storage roll, with one function being to prevent the adhesive side from sticking strongly to the non-adhesive side. Of course, a release film is ordinarily needed if the one-sided adhesive cushion is to be installed with the adhesive side up, for engagement with the carpet backing.